GEO & AI search

Custom channel group

Definition

A copy of GA4's default channel group that you can edit: add channels, change conditions and reorder them. Traffic goes to the first channel whose definition it matches. Standard properties can have two custom groups, 360 properties five, each with up to 50 channels. Google says custom groups can be applied to reports retroactively.

Defined in GA4's AI Assistant Channel: What It Counts, What It Misses, and the Regex for the Rest.

How else it gets framed

The same term carries different emphasis depending on the surface it’s used on. Both readings are correct.

Your own set of rule-based channels in GA4, created by copying the default group and editing it. Google says traffic goes into the first channel whose definition it matches, and that custom groups can be applied to reports retroactively.

The Monthly AI-Attributed Revenue Report: What to Put in It and How to Build It →

Where Custom channel group comes up

The guides that put this term to work, rather than just defining it.

Related terms

Default channel group: GA4's built-in set of rules that sorts every session into a channel such as Organic Search, Paid Search, Referral, Direct or AI Assistant, based on source, medium and campaign. Google says you can't edit it. You can copy it into a custom channel group and change the copy.
AI-attributed revenue: Purchase revenue from sessions whose source GA4 can identify as an AI assistant, using last-click attribution within the session. It excludes purchases influenced by AI answers that arrived through Organic Search, Direct or another channel, so it understates AI's total effect.
AI Assistant channel: A channel in GA4's default channel group for visits from AI assistants such as ChatGPT, Gemini, Deepseek, Copilot and Grok. Its rule is that the medium exactly matches ai-assistant. GA4 sets that medium, and the campaign (ai-assistant), when the referrer matches Google's list of AI assistants. Google says the channel excludes its own AI Overviews and AI Mode.
OpenAI Measurement Pixel: OpenAI's browser SDK for ChatGPT Ads. You install a script, initialize it with a Pixel ID created in the Conversions section of Ads Manager, and call oaiq("measure", ...) when a conversion happens, such as order_created for a purchase.
Conversions API: OpenAI's server-to-server endpoint for ChatGPT Ads conversion events. Your backend posts confirmed events, such as a paid order, with a Pixel ID and a separate Conversions API key. OpenAI calls it a more reliable tracking source than the Pixel alone.
oppref: The OpenAI click reference appended to the end of a ChatGPT ad's landing page URL (for example ?oppref=gAAAAAb123). The Pixel captures it and stores it in a first-party __oppref cookie for 30 days; server events should pass the original value unchanged.

All 157 terms

What is AI invisibility costing you?

Revenue at risk from AI shopping channels, with the formula shown so you can check the maths.

Open the calculator Commerce GEO